Generally, many types of viscous cleansing materials (such as facial cleansers, toothpaste, etc.), in form of gels, liquids, paste, and the like, are each filled in a respective collapsible tube, and are dispensed therefrom by pressing the collapsible tube with a user's hand. Many squeezing devices have been proposed and used to aid in expelling of the viscous material from the collapsible tube. A common squeezer includes a flat elongated plate formed with a slot so as to be sleeved on a sealed end of the collapsible tube in use, such that the squeezer can be pushed forwardly toward an opened end to expel the viscous material from the collapsible tube. However, it is known that such squeezer cannot efficiently expel all of the viscous material due to the large size of the slot. Reducing the size of the slot renders sleeving of the squeezer on the collapsible tube inconvenient and troublesome. Another conventional squeezer has been developed to express the viscous material from a collapsible tube and wind up the emptied tube portion on a rotary shaft. Such squeezer has a relatively complicated structure that is inconvenient to manufacture and not easy to use.